Asthma is usually viewed as an airways disease where chronic inflammation plays an important role in pathogenesis. Some studies have used bronchoalveolar lavage (BAL) to assess airway inflammation by examining the fluids and cells recovered by this procedure. This approach has demonstrated levels of multiple inflammatory mediators such as histamine, tryptase, prostaglandins, leukotrienes, and kinins in BAL fluids from asthmatic subjects compared to normal subjects, as well as increased numbers of inflammatory cells, such as mast cells and eosinophils. Some of these abnormalities have been directly correlated with disease severity, decreased pulmonary function, and airway hyperactivity. The purpose of this study is to examine the relationship between inflammation assessed by examination of cells and mediators in BAL fluids and inflammation in airways assessed by bronchial biopsy.